Wave propagation in 2-D elastic media using a spectral element method withtriangles and quadrangles

We apply a spectral element method based upon a conforming mesh of quadrang les and triangles to the problem of 2-D elastic wave propagation. The metho d retains the advantages of classical spectral element methods based upon q uadrangles only. It makes use of the classical Gauss-Lobatto-Legendre formu lation on the quadrangles, while discretization on the triangles is based u pon interpolation at the Fekete points. We obtain a global diagonal mass ma trix which allows us to keep the explicit structure of classical spectral e lement solvers. We demonstrate the accuracy and efficiency of the method by comparing results obtained for pure quadrangle meshes with those obtained using mixed quadrangle-triangle and triangle-only meshes.